Bhashya
एष उ एव भामनीः, एष हि यस्मात् सर्वेषु लोकेषु आ-दित्यचन्द्राग्न्यादिरूपैः भाति दीप्यते, 'तस्य भासा सर्वमिदंविभाति' इति श्रुतेः ।अतो भामानि नयतीति भामनीः ।य एवं वेद, असावपि सर्वेषु लोकेषु भाति ॥
In plain words
He alone is the leader of light, because he shines across all worlds through the forms of sun, moon, and fire, as the scripture declares: 'By his light all this shines forth.' Therefore, because he leads these lights, he is called Bhāmanīḥ. And whoever knows him thus also shines throughout all worlds.
Close to the Sanskrit
This indeed is the leader of light; because in all worlds he shines, blazes forth, in forms such as sun, moon, and fire, from the scriptural text: 'By his light all this shines forth.' Hence, because he leads lights, he is the leader of light. He who thus knows, that one also shines in all worlds.